Counterfeit document detector

ABSTRACT

A housing has a structural portion which forms a light shield and another structural portion adjacent to the light shield which forms an easel suitable for supporting a document to be verified such as currency. An ultraviolet lamp is mounted behind the light shield such that the ultraviolet energy therefrom strikes the currency. Counterfeit currency is readily detected by virtue of a characteristic blue glow that it gives off.

United States Patent [191 Goodrich [451 Oct. 15, 1974 COUNTERFEITDOCUMENT DETECTOR [76] Inventor: Robert S. Goodrich, 27901 S.

Golden Meadow Dr., Palos Verdes [22] Filed: Feb. 5, 1973 [21] Appl. No.:329,456

[52] US. Cl 250/461, 250/485, 250/491 [51] Int. Cl. G0ld 7/06 [58] Fieldof Search 250/365, 461, 485; 356/71 [56] References Cited UNITED STATESPATENTS 2,059,197 11/1936 Backer et al 356/71 2,161,594 6/1939 Ruth356/71 9/1969 Hubert 250/304 Hubert 250/461 l-loch et al. 250/485Primary Examiner-James W. Lawrence Assistant Examiner-Davis L. WillisAttorney, Agent, or Firm-Edward A. Sokolski [57 ABSTRACT A housing has astructural portion which forms a light shield and another structuralportion adjacent to the light shield which forms an easel suitable forsupporting a document to be verified such as currency. An ultravioletlamp is mounted behind the light shield such that the ultraviolet energytherefrom strikes the currency. Counterfeit currency is readily detectedby virtue of a characteristic blue glow that it gives off.

4 Claims, 4 Drawing Figures COUNTERFEIT DOCUMENT DETECTOR This inventionrelates to a counterfeit document detector and more particularly to sucha device utilizing ultraviolet light in identifying counterfeitcurrency.

The unwitting acceptance of counterfeit currency has been a problem formany years in view of the difficulty of any but the most expert intelling good money from bad. This is a particular problem in situationswhere a good deal of currency is rapidly passed, such as in supermarkets, department stores and banks, in view of the lack of time forthe cashier or teller to examine the bills except in a very cursoryfashion. Where bills are expertly counterfeited, they tend to pass asreal except when examined by experts.

It has been found that most counterfeit currency has a chromamorphicresponse or color change when it is viewed in ultraviolet light suchthat it fluoresces with a bluish light glow. This is due to bleach orphotochemicals used in the paper used for most counterfeit money.Genuine currency is printed on a special paper manu factured understrict government control which has no bleach or chemicals therein.Thus, genuine currency will not glow in the fashion just described whensubjected to ultraviolet light.

, The device of this invention provides a simple, convenient device ofeconomical construction to facilitate the examination of bills and otherdocuments under ultraviolet light to verify their authenticity. Thedevice of the invention is of compact construction and can be placed ona counter where it occupies a minimum of space. I

It is therefore an object of this invention to facilitate the detectionof counterfeit currency and other counterfeit documents.

Another object of this invention is to provide a compact, inexpensivedevice for enabling the rapid and accurate checking of currency.

Other objects of the invention will become apparent as the descriptionproceeds in connection with the accompanying drawings, of which:

FIG. 1 is a perspective view of one embodiment of the invention;

F IG. 2 is a cross-sectional view taken along the plane indicated by 22in FIG. 1;

F lG. 3 is a cross-sectional view taken along the plane indicatedby 3-3in FIG. 2; and

FIG. 4 is a cross-sectional view taken along the plane indicated by 4-4in HQ 2.

Briefly described, the device of the invention comprises a housing withan ultraviolet lamp mounted therein and a switch and transformerforenabling the operation of such lamp from an AC power line. A portionof the casing is shaped to form a light shield for the ultraviolet lamp,this shield directing the light from the lamp towards another portion ofthe casing which forms an easel on which the currency to be examined canbe placed. The easel portion of the casing provides a housing for atransformer for providing power to the lamp. A pair of removable endplates are provided to facilitate assembly of the device, one of theseend plates having a lamp switch mounted therein. Currency and otherdocuments can then be placed on the easel with the ultraviolet lightdirected thereagainst for rapid identification.

Referring now to the figures, the casing 11 has a light shield 12 formedalong the front thereof. Supported in the casing behind light shield 12in a pair of lamp sockets 14 is ultraviolet lamp 15. The upper portion12a of light shield 12 wraps around lamp 15 so as to direct the lightoutput thereof towards the face 17a of easel portion 17 of the casing.Power is provided for lamp 15 through power cord 18 which is connectedto the AC power line. The AC voltage is stepped down to an appropriatevalue for the lamp by means of transformer 20 which is mounted in theeasel portion of the casing. The lamp power is switched on and off bymeans of switch 22 mounted on end plate 25. End plate 25 is removablyattached to the main body of the casing by means of screws 28, thusfacilitating the removal of the plate to repair or replace the variousparts. I

Easel portion 17 has a flat surface 17a which is slanted away from lampl5 and extends from directly opposite the lamp to a line above the edgeof shield portion 12a. The easel thus provides a convenient support fora bill 25 or other document to be examined. Easel portion 17 also has awall 17b which slants away from surface 17a and forms the rear wall ofthe casing. The lower portion of such bill 25 is positioned directlyopposite and in close proximity to the lamp in a location where thelight emissions thereof are shielded by shield 12 while at the same timethesebottom bill portions can be readily viewed from above by anobserver. Easel l7 and shield 12 can each be fabricated from singlepieces of sheet metal bent to the desired configura-- tions, making forhighly simple and economical construction.

As already noted, when avalid piece of currency 25 is exposed to theultraviolet light, lamp 15, there is no glow or color change. Acounterfeit bill, on the other hand, will glow with a bright bluefluorescent color.

The device ofthe invention thus provides a simple and economical meanswhich can be mounted on'a smaller corner of the counter for checking thevalidity of currency. I v

While the device of the invention has been described and illustrated indetail, it is to be clearly understood that this is intended by way ofillustration and example only, and is not to be taken by way oflimitation, the spirit and scope of this invention being limited only bythe terms of the following claims. a

I claim:

l. A device for checking the comprising:

a casing having a first portion thereof shaped to form a light shield,and a second portion thereof shaped to form an easel for supporting adocument to be examined,

an ultraviolet lamp mounted in said casing adjacent to and behind saidlight shield, said light shield having a part thereof which wraps aroundsaid lamp,

validity of a document said easel portion extending at a slant anglefrom opposite said lamp away from the lamp to a line above the edge ofthe wrap-around part of said light shield, said light shield directingthe light from said lamp towards said easel portion, and means forselectively energizing said ultraviolet lamp,

2. The device of claim 1 wherein said light shield extends along a frontedge of said casing and said easel includes a flat, front portionpositioned opposite said light shield and slanted away from said shieldand the back portion which forms the rear wall of the casing.

3. The device of claim 1 and further including end plates removablyattached to the opposite ends of said said transformer.

1. A device for checking the validity of a document comprising: a casinghaving a first portion thereof shaped to form a light shield, and asecond portion thereof shaped to form an easel for supporting a documentto be examined, an ultraviolet lamp mounted in said casing adjacent toand behind said light shield, said light shield having a part thereofwhich wraps around said lamp, said easel portion extending at a slantangle from opposite said lamp away from the lamp to a line above theedge of the wraparound part of said light shield, said light shielddirecting the light from said lamp towards said easel portion, and meansfor selectively energizing said ultraviolet lamp, whereby a document tobe examined can be placed on said easel such that the bottom portionsthereof lie opposite said lamp and shielded by said light shield toreceive a substantial portion of the light output of the lamp, yetviewable from above.
 2. The device of claim 1 wherein said light shieldextends along a front edge of said casing and said easel includes aflat, front portion positioned opposite said light shield and slantedaway from said shield and the back portion which forms the rear wall ofthe casing.
 3. The device of claim 1 and further including end platesremovably attached to the opposite ends of said casing.
 4. The device ofclaim 1 wherein said means for selectively energizing said lampcomprises a poweR line, a transformer mounted in said casing beneathsaid easel, and an electrical switch mounted in one of said end platesfor connecting power from said power line to said transformer.